The present invention relates to the field of television and tele-display, more particularly that of display, on a viewing screen or cathoscope, of an added "label" inserted locally into an image. More precisely, the invention relates to the synchronization of the label with the vertical and horizontal scanning of the screen.
It frequently happens that complementary information is added to viewing screen. This information may for example--and without the cases cited being limiting--be the display of the selected channel or the time on a domestic television reception screen, or the display of parameters on a graphic tele-data processing console.
The legibility of the labels implies a good stability thereof with respect to the image, i.e. good synchronization of the scan generating the image and of the scan generating and label: it is a solution in this problem of synchronization which the device of the invention provides.
To obtain the stability of the labels, the device of the invention links the triggering of the display to a current in the coil of the deflector of the cathoscope tube.